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Mittal S, Mallia MB. Molecular imaging of tumor hypoxia: Evolution of nitroimidazole radiopharmaceuticals and insights for future development. Bioorg Chem 2023; 139:106687. [PMID: 37406518 DOI: 10.1016/j.bioorg.2023.106687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/15/2023] [Indexed: 07/07/2023]
Abstract
Though growing evidence has been collected in support of the concept of dose escalation based on the molecular level images indicating hypoxic tumor sub-volumes that could be radio-resistant, validation of the concept is still a work in progress. Molecular imaging of tumor hypoxia using radiopharmaceuticals is expected to provide the required input to plan dose escalation through Image Guided Radiation Therapy (IGRT) to kill/control the radio-resistant hypoxic tumor cells. The success of the IGRT, therefore, is heavily dependent on the quality of images obtained using the radiopharmaceutical and the extent to which the image represents the true hypoxic status of the tumor in spite of the heterogeneous nature of tumor hypoxia. Available literature on radiopharmaceuticals for imaging hypoxia is highly skewed in favor of nitroimidazole as the pharmacophore given their ability to undergo oxygen dependent reduction in hypoxic cells. In this context, present review on nitroimidazole radiopharmaceuticals would be immensely helpful to the researchers to obtain a birds-eye view on what has been achieved so far and what can be tried differently to obtain a better hypoxia imaging agent. The review also covers various methods of radiolabeling that could be utilized for developing radiotracers for hypoxia targeting applications.
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Affiliation(s)
- Sweety Mittal
- Radiopharmaceuticals Division, Bhabha Atomic Research Center, Mumbai 400085, India.
| | - Madhava B Mallia
- Radiopharmaceuticals Division, Bhabha Atomic Research Center, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India.
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Kniess T, Zessin J, Mäding P, Kuchar M, Kiss O, Kopka K. Synthesis of [ 18F]FMISO, a hypoxia-specific imaging probe for PET, an overview from a radiochemist's perspective. EJNMMI Radiopharm Chem 2023; 8:5. [PMID: 36897480 PMCID: PMC10006378 DOI: 10.1186/s41181-023-00190-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 02/20/2023] [Indexed: 03/11/2023] Open
Abstract
BACKGROUND [18F]fluoromisonidazole ([18F]FMISO, 1H-1-(3-[18F]fluoro-2-hydroxypropyl)-2-nitroimidazole) is a commonly used radiotracer for imaging hypoxic conditions in cells. Since hypoxia is prevalent in solid tumors, [18F]FMISO is in clinical application for decades to explore oxygen demand in cancer cells and the resulting impact on radiotherapy and chemotherapy. RESULTS Since the introduction of [18F]FMISO as positron emission tomography imaging agent in 1986, a variety of radiosynthesis procedures for the production of this hypoxia tracer has been developed. This paper gives a brief overview on [18F]FMISO radiosyntheses published so far from its introduction until now. From a radiopharmaceutical chemist's perspective, different precursors, radiolabeling approaches and purification methods are discussed as well as used automated radiosynthesizers, including cassette-based and microfluidic systems. CONCLUSION In a GMP compliant radiosynthesis using original cassettes for FASTlab we produced [18F]FMISO in 49% radiochemical yield within 48 min with radiochemical purities > 99% and molar activities > 500 GBq/µmol. In addition, we report an easy and efficient radiosynthesis of [18F]FMISO, based on in-house prepared FASTlab cassettes, providing the radiotracer for research and preclinical purposes in good radiochemical yields (39%), high radiochemical purities (> 99%) and high molar activity (> 500 GBq/µmol) in a well-priced option.
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Affiliation(s)
- Torsten Kniess
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany.
| | - Jörg Zessin
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
| | - Peter Mäding
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
| | - Manuela Kuchar
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
| | - Oliver Kiss
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany
| | - Klaus Kopka
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany.,Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Mommsenstraße 4, 01069, Dresden, Germany.,National Center for Tumor Diseases (NCT) Dresden, University Hospital Carl Gustav Carus, Fetscherstraße 74, 01307, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, Fetscherstraße 74, 01307, Dresden, Germany
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Castellano A, Bailo M, Cicone F, Carideo L, Quartuccio N, Mortini P, Falini A, Cascini GL, Minniti G. Advanced Imaging Techniques for Radiotherapy Planning of Gliomas. Cancers (Basel) 2021; 13:cancers13051063. [PMID: 33802292 PMCID: PMC7959155 DOI: 10.3390/cancers13051063] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 02/24/2021] [Accepted: 02/26/2021] [Indexed: 02/07/2023] Open
Abstract
The accuracy of target delineation in radiation treatment (RT) planning of cerebral gliomas is crucial to achieve high tumor control, while minimizing treatment-related toxicity. Conventional magnetic resonance imaging (MRI), including contrast-enhanced T1-weighted and fluid-attenuated inversion recovery (FLAIR) sequences, represents the current standard imaging modality for target volume delineation of gliomas. However, conventional sequences have limited capability to discriminate treatment-related changes from viable tumors, owing to the low specificity of increased blood-brain barrier permeability and peritumoral edema. Advanced physiology-based MRI techniques, such as MR spectroscopy, diffusion MRI and perfusion MRI, have been developed for the biological characterization of gliomas and may circumvent these limitations, providing additional metabolic, structural, and hemodynamic information for treatment planning and monitoring. Radionuclide imaging techniques, such as positron emission tomography (PET) with amino acid radiopharmaceuticals, are also increasingly used in the workup of primary brain tumors, and their integration in RT planning is being evaluated in specialized centers. This review focuses on the basic principles and clinical results of advanced MRI and PET imaging techniques that have promise as a complement to RT planning of gliomas.
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Affiliation(s)
- Antonella Castellano
- Neuroradiology Unit, IRCCS Ospedale San Raffaele and Vita-Salute San Raffaele University, 20132 Milan, Italy; (A.C.); (A.F.)
| | - Michele Bailo
- Department of Neurosurgery and Gamma Knife Radiosurgery, IRCCS Ospedale San Raffaele and Vita-Salute San Raffaele University, 20132 Milan, Italy; (M.B.); (P.M.)
| | - Francesco Cicone
- Department of Experimental and Clinical Medicine, “Magna Graecia” University of Catanzaro, and Nuclear Medicine Unit, University Hospital “Mater Domini”, 88100 Catanzaro, Italy;
- Correspondence: ; Tel.: +39-0-961-369-4155
| | - Luciano Carideo
- National Cancer Institute, G. Pascale Foundation, 80131 Naples, Italy;
| | - Natale Quartuccio
- A.R.N.A.S. Ospedale Civico Di Cristina Benfratelli, 90144 Palermo, Italy;
| | - Pietro Mortini
- Department of Neurosurgery and Gamma Knife Radiosurgery, IRCCS Ospedale San Raffaele and Vita-Salute San Raffaele University, 20132 Milan, Italy; (M.B.); (P.M.)
| | - Andrea Falini
- Neuroradiology Unit, IRCCS Ospedale San Raffaele and Vita-Salute San Raffaele University, 20132 Milan, Italy; (A.C.); (A.F.)
| | - Giuseppe Lucio Cascini
- Department of Experimental and Clinical Medicine, “Magna Graecia” University of Catanzaro, and Nuclear Medicine Unit, University Hospital “Mater Domini”, 88100 Catanzaro, Italy;
| | - Giuseppe Minniti
- Radiation Oncology Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Policlinico Le Scotte, 53100 Siena, Italy;
- IRCCS Neuromed, 86077 Pozzilli (IS), Italy
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Sanduleanu S, van der Wiel AM, Lieverse RI, Marcus D, Ibrahim A, Primakov S, Wu G, Theys J, Yaromina A, Dubois LJ, Lambin P. Hypoxia PET Imaging with [18F]-HX4-A Promising Next-Generation Tracer. Cancers (Basel) 2020; 12:cancers12051322. [PMID: 32455922 PMCID: PMC7280995 DOI: 10.3390/cancers12051322] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 02/04/2023] Open
Abstract
Hypoxia—a common feature of the majority of solid tumors—is a negative prognostic factor, as it is associated with invasion, metastasis and therapy resistance. To date, a variety of methods are available for the assessment of tumor hypoxia, including the use of positron emission tomography (PET). A plethora of hypoxia PET tracers, each with its own strengths and limitations, has been developed and successfully validated, thereby providing useful prognostic or predictive information. The current review focusses on [18F]-HX4, a promising next-generation hypoxia PET tracer. After a brief history of its development, we discuss and compare its characteristics with other hypoxia PET tracers and provide an update on its progression into the clinic. Lastly, we address the potential applications of assessing tumor hypoxia using [18F]-HX4, with a focus on improving patient-tailored therapies.
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Affiliation(s)
- Sebastian Sanduleanu
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW—School for Oncology, Maastricht University, 6211 Maastricht, The Netherlands; (A.M.A.v.d.W.); (R.I.Y.L.); (D.M.); (A.I.); (S.P.); (G.W.); (J.T.); (A.Y.); (L.J.D.); (P.L.)
- Correspondence:
| | - Alexander M.A. van der Wiel
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW—School for Oncology, Maastricht University, 6211 Maastricht, The Netherlands; (A.M.A.v.d.W.); (R.I.Y.L.); (D.M.); (A.I.); (S.P.); (G.W.); (J.T.); (A.Y.); (L.J.D.); (P.L.)
| | - Relinde I.Y. Lieverse
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW—School for Oncology, Maastricht University, 6211 Maastricht, The Netherlands; (A.M.A.v.d.W.); (R.I.Y.L.); (D.M.); (A.I.); (S.P.); (G.W.); (J.T.); (A.Y.); (L.J.D.); (P.L.)
| | - Damiënne Marcus
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW—School for Oncology, Maastricht University, 6211 Maastricht, The Netherlands; (A.M.A.v.d.W.); (R.I.Y.L.); (D.M.); (A.I.); (S.P.); (G.W.); (J.T.); (A.Y.); (L.J.D.); (P.L.)
| | - Abdalla Ibrahim
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW—School for Oncology, Maastricht University, 6211 Maastricht, The Netherlands; (A.M.A.v.d.W.); (R.I.Y.L.); (D.M.); (A.I.); (S.P.); (G.W.); (J.T.); (A.Y.); (L.J.D.); (P.L.)
- Department of Radiology and Nuclear Medicine, GROW—School for Oncology and Developmental Biology, Maastricht University Medical Centre+, 6229 Maastricht, The Netherlands
- Division of Nuclear Medicine and Oncological Imaging, Department of Medical Physics, Hospital Center Universitaire De Liege, 4030 Liege, Belgium
- Department of Nuclear Medicine and Comprehensive Diagnostic Center Aachen (CDCA), University Hospital RWTH Aachen University, 52074 Aachen, Germany
| | - Sergey Primakov
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW—School for Oncology, Maastricht University, 6211 Maastricht, The Netherlands; (A.M.A.v.d.W.); (R.I.Y.L.); (D.M.); (A.I.); (S.P.); (G.W.); (J.T.); (A.Y.); (L.J.D.); (P.L.)
| | - Guangyao Wu
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW—School for Oncology, Maastricht University, 6211 Maastricht, The Netherlands; (A.M.A.v.d.W.); (R.I.Y.L.); (D.M.); (A.I.); (S.P.); (G.W.); (J.T.); (A.Y.); (L.J.D.); (P.L.)
| | - Jan Theys
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW—School for Oncology, Maastricht University, 6211 Maastricht, The Netherlands; (A.M.A.v.d.W.); (R.I.Y.L.); (D.M.); (A.I.); (S.P.); (G.W.); (J.T.); (A.Y.); (L.J.D.); (P.L.)
| | - Ala Yaromina
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW—School for Oncology, Maastricht University, 6211 Maastricht, The Netherlands; (A.M.A.v.d.W.); (R.I.Y.L.); (D.M.); (A.I.); (S.P.); (G.W.); (J.T.); (A.Y.); (L.J.D.); (P.L.)
| | - Ludwig J. Dubois
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW—School for Oncology, Maastricht University, 6211 Maastricht, The Netherlands; (A.M.A.v.d.W.); (R.I.Y.L.); (D.M.); (A.I.); (S.P.); (G.W.); (J.T.); (A.Y.); (L.J.D.); (P.L.)
| | - Philippe Lambin
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW—School for Oncology, Maastricht University, 6211 Maastricht, The Netherlands; (A.M.A.v.d.W.); (R.I.Y.L.); (D.M.); (A.I.); (S.P.); (G.W.); (J.T.); (A.Y.); (L.J.D.); (P.L.)
- Department of Radiology and Nuclear Medicine, GROW—School for Oncology and Developmental Biology, Maastricht University Medical Centre+, 6229 Maastricht, The Netherlands
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Anjum R, Palanimuthu D, Kalinowski DS, Lewis W, Park KC, Kovacevic Z, Khan IU, Richardson DR. Synthesis, Characterization, and in Vitro Anticancer Activity of Copper and Zinc Bis(Thiosemicarbazone) Complexes. Inorg Chem 2019; 58:13709-13723. [PMID: 31339305 DOI: 10.1021/acs.inorgchem.9b01281] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of eight bis(thiosemicarbazone) ligands and 16 of their respective copper(II) and zinc(II) complexes containing a combination of hydrogen, methyl, pyridyl, phenyl, and/or ethyl substituents at the diimine position of the ligand backbone were synthesized and characterized. The objective of this study was to identify the structure-activity relationships within a series of analogues with different substituents at the diimine position of the backbone and at the terminal N atom. The Cu(II) complexes Cu(GTSM2), Cu(GTSCM), Cu(PyTSM2), Cu(EMTSM2) and Cu(PGTSM2) demonstrated a distorted square planar geometry, while the Zn(II) complexes Zn(ATSM2)(DMSO), Zn(PyTSM2)(DMSO), and Zn(PGTSM2)(H2O) formed a distorted square pyramidal geometry. Cyclic voltammetry showed that the Cu(II) complexes display quasi-reversible electrochemistry. Of the agents, Cu(II) glyoxal bis(4,4-dimethyl-3-thiosemicarbazone) [Cu(GTSM2)] and Cu(II) diacetyl bis(4,4-dimethyl-3-thiosemicarbazone) [Cu(ATSM2)] demonstrated the greatest antiproliferative activity against tumor cells. Substitutions at the diimine position and at the terminal N atom with hydrophobic moieties markedly decreased their antiproliferative activity. Complexation of the bis(thiosemicarbazones) with Zn(II) generally decreased their antiproliferative activity, suggesting the Zn(II) complex did not act as a chaperone to deliver the ligand intracellularly, in contrast to similar bis(thiosemicarbazone) cobalt(III) complexes [King et al. Inorg. Chem. 2017, 56, 6609-6623]. However, five of the eight bis(thiosemicarbazone) Cu(II) complexes maintained or increased their antiproliferative activity, relative to the ligand alone, and a mechanism of Cu-induced oxidative stress is suggested. Surprisingly, relative to normoxic growth conditions, hypoxia that is found in the tumor microenvironment decreased the antiproliferative efficacy of most bis(thiosemicarbazones) and their copper complexes. This was independent of the potential hypoxia-selectivity mediated by Cu(II/I) redox potentials. These results provide structure-activity relationships useful for the rational design of bis(thiosemicarbazone) anticancer agents.
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Affiliation(s)
- Rukhsana Anjum
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Duraippandi Palanimuthu
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Danuta S Kalinowski
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - William Lewis
- School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Kyung Chan Park
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Zaklina Kovacevic
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Irfan Ullah Khan
- Division of Cyclotron and Allied Radiopharmaceutics , INMOL Cancer Hospital , New Campus Road , Lahore 54600 , Pakistan
| | - Des R Richardson
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute , The University of Sydney , Sydney , New South Wales 2006 , Australia.,Department of Pathology and Biological Responses , Nagoya University Graduate School of Medicine , 65 Tsurumai , Showa-ku , Nagoya 466-8550 , Japan
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Synthesis and bioevaluation of novel radioiodinated PEG-modified 2-nitroimidazole derivatives for tumor hypoxia imaging. J Radioanal Nucl Chem 2019. [DOI: 10.1007/s10967-019-06649-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Elsaidi HR, Yang XH, Ahmadi F, Weinfeld M, Wiebe LI, Kumar P. Putative electron-affinic radiosensitizers and markers of hypoxic tissue: Synthesis and preliminary in vitro biological characterization of C3-amino-substituted benzotriazine dioxides (BTDOs). Eur J Med Chem 2019; 165:216-224. [PMID: 30684798 DOI: 10.1016/j.ejmech.2019.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/04/2019] [Accepted: 01/05/2019] [Indexed: 01/16/2023]
Abstract
INTRODUCTION The redox characteristics of 1,2,4-benzotriazine-1,4-dioxides (BTDOs) make them potential radiosensitizing agents for hypoxic cells in solid human cancers. Tirapazamine (TPZ) is the most clinically tested BTDO radiosensitizer, despite its toxicity at effective doses. To date, no BTDOs have been developed as diagnostic markers of tissue hypoxia. HYPOTHESIS TPZ analogues with appropriate reporting groups can act as potential radiosensitizers and hypoxia selective diagnostics. EXPERIMENTAL AND RESULTS 3-Chloro-1,2,4-benzotriazine 1-oxide was substituted at the C3 position to afford 3-(2-hydroxyethoxyethyl)-amino-1,2,4-benzotriazine-1-oxide, which was oxidized to 3-(2-hydroxyethoxyethyl)-amino-1,2,4-benzotriazine-1,4-dioxide (HO-EOE-TPZ) or converted to 3-(2-tosyloxyethoxyethyl)-amino-1,2,4-benzotriazine-1,4-dioxide (Tos-EOE-TPZ). Tos-EOE-TPZ was intended for use as a synthon for preparing 3-(2-azidoethoxyethyl)-amino-1,2,4-benzotriazine-1,4-dioxide (N3-EOE-TPZ) and 3-(2-iodoethoxyethyl)-amino-1,2,4-benzotriazine-1,4-dioxide (I-EOE-TPZ). The logP values (-0.69 to 0.61) for these molecules bracketed that of TPZ (-0.34). Cell line dependent cytotoxicities (IC50) in air were in the 10-100 μM range, with Hypoxia Cytotoxicity Ratios (HCR; IC50-air/IC50-hypoxia) of 5-10. LUMO calculations indicated that these molecules are in the optimal redox range for radiosensitization, offering cell-line-specific Relative Radiosensitization Ratios (RRSR; SER/OER) of 0.58-0.88, compared to TPZ (0.67-0.76). CONCLUSION The LUMO, IC50, HCR and RRSR values of 3-(2-substituted ethoxyethyl)-amino-1,2,4-benzotriazine-1,4-dioxides are similar to the corresponding values for TPZ, supporting the conclusion that these TPZ analogues are potentially useful as hypoxia-activated radiosensitizers. Further studies into their biodistributions in animal models are being pursued to determine the in vivo potential in hypoxia management.
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Affiliation(s)
- Hassan Rh Elsaidi
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, 11560 University Avenue Edmonton, Alberta, T6G 1Z2, Canada
| | - Xiao-Hong Yang
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, 11560 University Avenue Edmonton, Alberta, T6G 1Z2, Canada
| | - Fatemeh Ahmadi
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, 11560 University Avenue Edmonton, Alberta, T6G 1Z2, Canada
| | - Michael Weinfeld
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, 11560 University Avenue Edmonton, Alberta, T6G 1Z2, Canada
| | - Leonard I Wiebe
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, 11560 University Avenue Edmonton, Alberta, T6G 1Z2, Canada; Joint Appointment to Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Piyush Kumar
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, 11560 University Avenue Edmonton, Alberta, T6G 1Z2, Canada.
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Development of [ 131I]I-EOE-TPZ and [ 131I]I-EOE-TPZMO: Novel Tirapazamine (TPZ)-Based Radioiodinated Pharmaceuticals for Application in Theranostic Management of Hypoxia. Pharmaceuticals (Basel) 2019; 12:ph12010003. [PMID: 30609671 PMCID: PMC6469288 DOI: 10.3390/ph12010003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/18/2018] [Accepted: 12/20/2018] [Indexed: 01/14/2023] Open
Abstract
Introduction: Benzotriazine-1,4-dioxides (BTDOs) such as tirapazamine (TPZ) and its derivatives act as radiosensitizers of hypoxic tissues. The benzotriazine-1-monoxide (BTMO) metabolite (SR 4317, TPZMO) of TPZ also has radiosensitizing properties, and via unknown mechanisms, is a potent enhancer of the radiosensitizing effects of TPZ. Unlike their 2-nitroimidazole radiosensitizer counterparts, radiolabeled benzotriazine oxides have not been used as radiopharmaceuticals for diagnostic imaging or molecular radiotherapy (MRT) of hypoxia. The radioiodination chemistry for preparing model radioiodinated BTDOs and BTMOs is now reported. Hypothesis: Radioiodinated 3-(2-iodoethoxyethyl)-amino-1,2,4-benzotriazine-1,4-dioxide (I-EOE-TPZ), a novel bioisosteric analogue of TPZ, and 3-(2-iodoethoxyethyl)-amino-1,2,4-benzotriazine-1-oxide (I-EOE-TPZMO), its monoxide analogue, are candidates for in vivo and in vitro investigations of biochemical mechanisms in pathologies that develop hypoxic microenvironments. In theory, both radiotracers can be prepared from the same precursors. Methods: Radioiodination procedures were based on classical nucleophilic [131I]iodide substitution on Tos-EOE-TPZ (P1) and by [131I]iodide exchange on I-EOE-TPZ (P2). Reaction parameters, including temperature, reaction time, solvent and the influence of pivalic acid on products’ formation and the corresponding radiochemical yields (RCY) were investigated. Results: The [131I]iodide labeling reactions invariably led to the synthesis of both products, but with careful manipulation of conditions the preferred product could be recovered as the major product. Radioiodide exchange on P2 in ACN at 80 ± 5 °C for 30 min afforded the highest RCY, 89%, of [131I]I-EOE-TPZ, which upon solid phase purification on an alumina cartridge gave 60% yield of the product with over 97% of radiochemical purity. Similarly, radioiodide exchange on P2 in ACN at 50 ± 5 °C for 30 min with pivalic acid afforded the highest yield, 92%, of [131I]I-EOE-TPZMO exclusively with no trace of [131I]I-EOE-TPZ. In both cases, extended reaction times and/or elevated temperatures resulted in the formation of at least two additional radioactive reaction products. Conclusions: Radioiodination of P1 and P2 with [131I]iodide leads to the facile formation of [131I]I-EOE-TPZMO. At 80 °C and short reaction times, the facile reduction of the N-4-oxide moiety was minimized to afford acceptable radiochemical yields of [131I]I-EOE-TPZ from either precursor. Regeneration of [131I]I-EOE-TPZ from [131I]I-EOE-TPZMO is impractical after reaction work-up.
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Sun W, Falzon C, Naimi E, Akbari A, Wiebe LI, Tandon M, Kumar P. Synthesis of [ 18F]FAZA Using Nosyl and Iodo Precursors for Nucleophilic Radiofluorination. Curr Radiopharm 2018; 12:49-57. [PMID: 30338747 DOI: 10.2174/1874471011666181019105947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 10/01/2018] [Accepted: 10/02/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND 1-α-D-(5-Deoxy-5-[18F]fluoroarabinofuranosyl)-2-nitroimidazole ([18F]FAZA) is manufactured by nucleophilic radiofluorination of 1-α-D-(2',3'-di-O-acetyl-5'-O-toluenesulfonylarabinofuranosyl)- 2-nitroimidazole (DiAcTosAZA) and alkaline deprotection to afford [18F]FAZA. High yields (>60%) under optimized conditions frequently revert to low yields (<20%) in large scale, automated syntheses. Competing side reactions and concomitant complex reaction mixtures contribute to substantial loss of product during HPLC clean-up. OBJECTIVE To develop alternative precursors for facile routine clinical manufacture of [18F]FAZA that are compatible with current equipment and automated procedures. METHODS Two new precursors, 1-α-D-(2',3'-di-O-acetyl-5'-O-(4-nitrobenzene)sulfonyl-arabinofuranosyl)-2- nitroimidazole (DiAcNosAZA) and 1-α-D-(2',3'-di-O-acetyl-5'-iodo-arabinofuranosyl)-2-nitroimidazole (DiAcIAZA), were synthesized from commercially-available 1-α-D-arabinofuranosyl-2-nitroimidazole (AZA). A commercial automated synthesis unit (ASU) was used to condition F-18 for anhydrous radiofluorination, and to radiofluorinate DiAcNosAZA and DiAcIAZA using the local standardized protocol to manufacture [18F]FAZA from AcTosAZA. RESULTS DiAcNosAZA was synthesized via two pathways, in recovered yields of 29% and 40%, respectively. The nosylation of 1-α-D-(2',3'-di-O-acetyl-arabinofuranosyl)-2-nitroimidazole (DiAcAZA) featured a strong competing reaction that afforded 1-α-D-(2',3'-di-O-acetyl-5'-chloro-arabinofuranosyl)-2- nitroimidazole (DiAcClAZA) in 55% yield. Radiofluorination yields were better from DiAcNosAZA and DiAcIAZA than from DiAcTosAZA, and the presence of fewer side products afforded higher purity [18F]FAZA preparations. Several radioactive and non-radioactive by products of radiofluorination were assigned tentative chemical structures based on co-chromatography with authentic reference compounds. CONCLUSION DiAcClAZA, a major side-product in the preparation of DiAcNosAZA, and its deprotected analogue (ClAZA), are unproven hypoxic tissue radiosensitizers. DiAcNosAZA and DiAcIAZA provided good radiofluorination yields in comparison to AcTosAZA and could become preferred [18F]FAZA precursors if the cleaner reactions can be exploited to bypass HPLC purification.
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Affiliation(s)
- William Sun
- Medimage Bionano Technology (Suzhou) Co. Ltd., Lab 408, building 15, 8 JinFeng Road, Suzhou New District, Jiangsu Province, Postcode 215163, China
| | - Cheryl Falzon
- Cyclotek (Aust) Pty Ltd., 38 Clements Avenue, Bundoora, Vic. 3083, Australia
| | - Ebrahim Naimi
- Naimi, Ebrahim Pharmacy Ltd., 9452 118 Ave NW, Edmonton, Alberta, Canada
| | - Ali Akbari
- Edmonton PET Centre, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta AB, Canada
| | - Leonard I Wiebe
- Department of Oncology, University of Alberta, and Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta AB, Canada
| | - Manju Tandon
- Department of Oncology, University of Alberta, and Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta AB, Canada
| | - Piyush Kumar
- Department of Oncology, University of Alberta, and Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta AB, Canada
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COX-2 Inhibition mediated anti-angiogenic activatable prodrug potentiates cancer therapy in preclinical models. Biomaterials 2018; 185:63-72. [PMID: 30223141 DOI: 10.1016/j.biomaterials.2018.09.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 08/26/2018] [Accepted: 09/06/2018] [Indexed: 12/31/2022]
Abstract
Anti-angiogenesis, i.e., blocking the angiogenic pathway, has been considered as an important component in current cancer therapeutic modalities. However, the associated benefits have proven to be modest as tumor angiogenesis and regrowth persist, probably due to other ill-defined complex angiogenic mechanisms. Herein, we developed an indomethacin (IMC) incorporating system to mediate hypoxia responsive prodrug (TA) and diagnostic agent (DA) in cancer theranostic applications. Cyclooxygenase 2 (COX-2) elevated expression in several cancer types is closely associated with severe tumor supporting vascularization factors. Our strategy utilizing COX-2 inhibition augmented the anti-angiogenetic induced hypoxia responsive prodrug activation well. Both in vitro and in vivo results proved that DA and TA exhibited specificity towards COX-2 positive (+ve) HeLa and A549 cancer cell lines and activation under hypoxic conditions. Compared with controls (R1, and anticancer drug SN-38), TA displayed prolonged tumor retention and enhanced therapeutic efficacy in xenograft mouse models at a reduced dosage. Our results significantly highlighted the importance of COX-2 blockade mediated anti-angiogenesis in complementing the hypoxia-responsive drug delivery systems (DDSs) and could to beneficial for the rapid development of more efficacious antitumor therapeutics.
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11
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Molecular Imaging-Guided Radiotherapy for the Treatment of Head-and-Neck Squamous Cell Carcinoma: Does it Fulfill the Promises? Semin Radiat Oncol 2018; 28:35-45. [PMID: 29173754 DOI: 10.1016/j.semradonc.2017.08.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
With the routine use of intensity modulated radiation therapy for the treatment of head-and-neck squamous cell carcinoma allowing highly conformed dose distribution, there is an increasing need for refining both the selection and the delineation of gross tumor volumes (GTV). In this framework, molecular imaging with positron emission tomography and magnetic resonance imaging offers the opportunity to improve diagnostic accuracy and to integrate tumor biology mainly related to the assessment of tumor cell density, tumor hypoxia, and tumor proliferation into the treatment planning equation. Such integration, however, requires a deep comprehension of the technical and methodological issues related to image acquisition, reconstruction, and segmentation. Until now, molecular imaging has had a limited value for the selection of nodal GTV, but there are increasing evidences that both FDG positron emission tomography and diffusion-weighted magnetic resonance imaging has a potential value for the delineation of the primary tumor GTV, effecting on dose distribution. With the apprehension of the heterogeneity in tumor biology through molecular imaging, growing evidences have been collected over the years to support the concept of dose escalation/dose redistribution using a planned heterogeneous dose prescription, the so-called "dose painting" approach. Validation trials are ongoing, and in the coming years, one may expect to position the dose painting approach in the armamentarium for the treatment of patients with head-and-neck squamous cell carcinoma.
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12
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Wardman P. Nitroimidazoles as hypoxic cell radiosensitizers and hypoxia probes: misonidazole, myths and mistakes. Br J Radiol 2018; 92:20170915. [PMID: 29303355 DOI: 10.1259/bjr.20170915] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Nitroimidazoles have been extensively explored as hypoxic cell radiosensitizers but have had limited clinical success, with efficacy restricted by toxicity. However, they have proven clinically useful as probes for tumour hypoxia. Both applications, and probably much of the dose-limiting toxicities, reflect the dominant chemical property of electron affinity or ease of reduction, associated with the nitro substituent in an aromatic structure. This single dominant property affords unusual, indeed extraordinary flexibility in drug or probe design, suggesting further development is possible in spite of earlier limitations, in particular building on the benefit of hindsight and an appreciation of errors made in earlier studies. The most notable errors were: the delay in viewing cellular thiol depletion as a likely common artefact in testing in vitro; slow recognition of pH-driven concentration gradients when compounds were weak acids and bases; and a failure to explore the possible involvement of pH and ascorbate in influencing hypoxia probe binding. The experience points to the need to involve a wider range of expertise than that historically involved in many laboratories when studying the effects of chemicals on radiation response or using diagnostic probes.
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Affiliation(s)
- Peter Wardman
- Formerly of the Gray Cancer Institute, University of Oxford, CRUK/MRC Oxford Institute for Radiation Oncology, Oxford, UK
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13
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Stypinski D, McQuarrie SA, McEwan AJB, Wiebe LI. Pharmacokinetics and Scintigraphic Imaging of the Hypoxia-Imaging Agent [ 123I]IAZA in Healthy Adults Following Exercise-Based Cardiac Stress †. Pharmaceutics 2018; 10:pharmaceutics10010025. [PMID: 29470434 PMCID: PMC5874838 DOI: 10.3390/pharmaceutics10010025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/16/2018] [Accepted: 02/16/2018] [Indexed: 11/16/2022] Open
Abstract
The objective of this work is to evaluate the potential effect of cardiac stress exercise on the accumulation of [123I]IAZA, a radiopharmaceutical used to image focal tissue hypoxia, in otherwise normal myocardium in healthy volunteers, and to determine the impact of exercise on [123I]IAZA pharmacokinetics. The underlying goal is to establish a rational basis and a baseline for studies of focal myocardial hypoxia in cardiac patients using [123I]IAZA. Three healthy male volunteers ran the ‘Bruce’ treadmill protocol, a clinically-accepted protocol designed to expose myocardial ischemia in patients. The ‘Bruce’ criterion heart rate is 85% of [220–age]. Approximately one minute before reaching this level, [123I]IAZA (5.0 mCi/0.85 mg) was administered as a slow (1–3 min) single intravenous (i.v.) injection via an indwelling venous catheter. The volunteer continued running for an additional 1 min before being transferred to a gamma camera. Serum samples were collected from the arm contralateral to the administration site at pre-determined intervals from 1 min to 45 h post injection and were analyzed by radio HPLC. Pharmacokinetic (PK) parameters were derived for [123I]IAZA and total radioactivity (total[123I]) using compartmental and noncompartmental analyses. Whole-body planar scintigraphic images were acquired from 0.75 to 24 h after dosing. PK data and scintigraphic images were compared to previously published [123I]IAZA data from healthy volunteers rest. Following exercise stress, both [123I]IAZA and total[123I] exhibited bi-exponential decline profiles, with rapid distribution phases [half-lives (t1/2α) of 1.2 and 1.4 min, respectively], followed by slower elimination phases [t1/2β of 195 and 290 min, respectively]. Total body clearance (CLTB) and the steady state volume of distribution (Vss) were 0.647 L/kg and 185 mL/min, respectively, for [123I]IAZA and 0.785 L/kg and 135 mL/min, respectively, for total[123I]. The t1/2β, CLTB and Vss values were comparable to those reported previously for rested volunteers. The t1/2α was approximately 4-fold shorter for [123I]IAZA and approximately 3-fold shorter for total[123I] under exercise relative to rested subjects. The heart region was visualized in early whole body scintigraphic images, but later images showed no accumulated radioactivity in this region, and no differences from images reported for rested volunteers were apparent. Minimal uptake of radiotracer in myocardium and skeletal muscle was consistent with uptake in non-stressed myocardium. Whole-body scintigrams for [123I]IAZA in exercise-stressed healthy volunteers were indistinguishable from images of non-exercised volunteers. There was no evidence of hypoxia-dependent binding in exercised but otherwise healthy myocardium, supporting the conclusion that exercise stress at Bruce protocol intensity does not induce measurable myocardial hypoxia. Effects of exercise on PK parameters were minimal; specifically, the t1/2α was shortened, reflecting increased cardiac output associated with exercise. It is concluded that because [123I]IAZA was not metabolically bound in exercise-stressed myocardium, a stress test will not create elevated myocardial background that would mask regions of myocardial perfusion deficiency. [123I]IAZA would therefore be suitable for the detection of viable, hypoxic myocardium in patients undergoing stress-test-based diagnosis.
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Affiliation(s)
- Daria Stypinski
- Pfizer Inc., Clinical Pharmacokinetics, Pfizer Inc., New York, NY 10017, USA.
| | - Stephen A McQuarrie
- PET Centre, Department of Oncology, University of Alberta, 11560 University Ave, Edmonton, AB T6B 1Z2, Canada.
- Faculty of Pharmacy and Pharmaceutical Sciences, and Department of Oncology, University of Alberta, Edmonton T6G 2R3, Canada; 2-40 Medical Isotope & Cyclotron Facility, University of Alberta-South Campus, Edmonton, AB T6H 2V8, Canada.
| | - Alexander J B McEwan
- PET Centre, Department of Oncology, University of Alberta, 11560 University Ave, Edmonton, AB T6B 1Z2, Canada.
| | - Leonard I Wiebe
- PET Centre, Department of Oncology, University of Alberta, 11560 University Ave, Edmonton, AB T6B 1Z2, Canada.
- Faculty of Pharmacy and Pharmaceutical Sciences, and Department of Oncology, University of Alberta, Edmonton T6G 2R3, Canada; 2-40 Medical Isotope & Cyclotron Facility, University of Alberta-South Campus, Edmonton, AB T6H 2V8, Canada.
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Chao PH, Collins J, Argus JP, Tseng WY, Lee JT, Michael van Dam R. Automatic concentration and reformulation of PET tracers via microfluidic membrane distillation. LAB ON A CHIP 2017; 17:1802-1816. [PMID: 28443841 PMCID: PMC5497730 DOI: 10.1039/c6lc01569g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Short-lived radiolabeled tracers for positron emission tomography (PET) must be rapidly synthesized, purified, and formulated into injectable solution just prior to imaging. Current radiosynthesizers are generally designed for clinical use, and the HPLC purification and SPE formulation processes often result in a final volume that is too large for preclinical and emerging in vitro applications. Conventional technologies and techniques for reducing this volume tend to be slow, resulting in radioactive decay of the product, and often require manual handling of the radioactive materials. We present a fully-automated microfluidic system based on sweeping gas membrane distillation to rapidly perform the concentration and formulation process. After detailed characterization of the system, we demonstrate fast and efficient concentration and formulation of several PET tracers, evaluate residual solvent content to establish the safety of the formulated tracers for injection, and show that the formulated tracer can be used for in vivo imaging.
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Affiliation(s)
- Philip H Chao
- Department of Bioengineering, Henry Samueli School of Engineering, UCLA, Los Angeles, CA 90095, USA.
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15
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Biological characterization of novel nitroimidazole-peptide conjugates in vitr
o and in vivo. J Pept Sci 2017; 23:597-609. [DOI: 10.1002/psc.2995] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/02/2017] [Accepted: 03/02/2017] [Indexed: 12/31/2022]
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16
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Cao J, Liu Y, Zhang L, Du F, Ci Y, Zhang Y, Xiao H, Yao X, Shi S, Zhu L, Kung HF, Qiao J. Synthesis of novel PEG-modified nitroimidazole derivatives via “hot-click” reaction and their biological evaluation as potential PET imaging agent for tumors. J Radioanal Nucl Chem 2017. [DOI: 10.1007/s10967-017-5210-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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17
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Efficient preparation of 2-nitroimidazole nucleosides as precursors for hypoxia PET tracers. MONATSHEFTE FUR CHEMIE 2017; 148:83-90. [PMID: 28127094 PMCID: PMC5225226 DOI: 10.1007/s00706-016-1874-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 11/06/2016] [Indexed: 11/03/2022]
Abstract
Abstract 2-Deoxy-D-ribose was converted to α/β-mixtures of methyl 3-O-acetyl- and methyl 3-O-benzoyl-2-deoxy-5-(p-toluenesulfonyl)-D-ribofuranosides. These were reacted with boron trichloride to generate ribofuranosyl chlorides, which afforded precursors for tracers to image tumor hypoxia on substitution with salts of 2-nitroimidazole. The anomeric ratio of the nucleosides was delicately influenced by the reaction conditions. Graphical abstract ![]()
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18
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Wanek T, Kreis K, Križková P, Schweifer A, Denk C, Stanek J, Mairinger S, Filip T, Sauberer M, Edelhofer P, Traxl A, Muchitsch VE, Mereiter K, Hammerschmidt F, Cass CE, Damaraju VL, Langer O, Kuntner C. Synthesis and preclinical characterization of 1-(6'-deoxy-6'-[ 18F]fluoro-β-d-allofuranosyl)-2-nitroimidazole (β-6'-[ 18F]FAZAL) as a positron emission tomography radiotracer to assess tumor hypoxia. Bioorg Med Chem 2016; 24:5326-5339. [PMID: 27614920 DOI: 10.1016/j.bmc.2016.08.053] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 08/16/2016] [Accepted: 08/27/2016] [Indexed: 12/31/2022]
Abstract
Positron emission tomography (PET) using fluorine-18 (18F)-labeled 2-nitroimidazole radiotracers has proven useful for assessment of tumor oxygenation. However, the passive diffusion-driven cellular uptake of currently available radiotracers results in slow kinetics and low tumor-to-background ratios. With the aim to develop a compound that is actively transported into cells, 1-(6'-deoxy-6'-[18F]fluoro-β-d-allofuranosyl)-2-nitroimidazole (β-[18F]1), a putative nucleoside transporter substrate, was synthetized by nucleophilic [18F]fluoride substitution of an acetyl protected labeling precursor with a tosylate leaving group (β-6) in a final radiochemical yield of 12±8% (n=10, based on [18F]fluoride starting activity) in a total synthesis time of 60min with a specific activity at end of synthesis of 218±58GBq/μmol (n=10). Both radiolabeling precursor β-6 and unlabeled reference compound β-1 were prepared in multistep syntheses starting from 1,2:5,6-di-O-isopropylidene-α-d-allofuranose. In vitro experiments demonstrated an interaction of β-1 with SLC29A1 and SLC28A1/2/3 nucleoside transporter as well as hypoxia specific retention of β-[18F]1 in tumor cell lines. In biodistribution studies in healthy mice β-[18F]1 showed homogenous tissue distribution and excellent metabolic stability, which was unaffected by tissue oxygenation. PET studies in tumor bearing mice showed tumor-to-muscle ratios of 2.13±0.22 (n=4) at 2h after administration of β-[18F]1. In ex vivo autoradiography experiments β-[18F]1 distribution closely matched staining with the hypoxia marker pimonidazole. In conclusion, β-[18F]1 shows potential as PET hypoxia radiotracer which merits further investigation.
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Affiliation(s)
- Thomas Wanek
- Biomedical Systems, AIT Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria.
| | - Katharina Kreis
- Biomedical Systems, AIT Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
| | - Petra Križková
- Institute of Organic Chemistry, University of Vienna, Währingerstraße 38, A-1090 Vienna, Austria
| | - Anna Schweifer
- Institute of Organic Chemistry, University of Vienna, Währingerstraße 38, A-1090 Vienna, Austria
| | - Christoph Denk
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163, A-1060 Vienna, Austria
| | - Johann Stanek
- Biomedical Systems, AIT Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
| | - Severin Mairinger
- Biomedical Systems, AIT Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
| | - Thomas Filip
- Biomedical Systems, AIT Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
| | - Michael Sauberer
- Biomedical Systems, AIT Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
| | - Patricia Edelhofer
- Biomedical Systems, AIT Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
| | - Alexander Traxl
- Biomedical Systems, AIT Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
| | - Viktoria E Muchitsch
- Biomedical Systems, AIT Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
| | - Kurt Mereiter
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164, A-1060 Vienna, Austria
| | - Friedrich Hammerschmidt
- Institute of Organic Chemistry, University of Vienna, Währingerstraße 38, A-1090 Vienna, Austria
| | - Carol E Cass
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Vijaya L Damaraju
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Oliver Langer
- Biomedical Systems, AIT Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria; Department of Clinical Pharmacology, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria
| | - Claudia Kuntner
- Biomedical Systems, AIT Austrian Institute of Technology GmbH, A-2444 Seibersdorf, Austria
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Schweifer A, Maier F, Ehrlichmann W, Lamparter D, Kneilling M, Pichler BJ, Hammerschmidt F, Reischl G. [ 18F]Fluoro-azomycin-2´-deoxy-β-d-ribofuranoside - A new imaging agent for tumor hypoxia in comparison with [ 18F]FAZA. Nucl Med Biol 2016; 43:759-769. [PMID: 27693670 DOI: 10.1016/j.nucmedbio.2016.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 07/25/2016] [Accepted: 08/07/2016] [Indexed: 01/30/2023]
Abstract
INTRODUCTION Radiolabeled 2-nitroimidazoles (azomycins) are a prominent class of biomarkers for PET imaging of hypoxia. [18F]Fluoro-azomycin-α-arabinoside ([18F]FAZA) - already in clinical use - may be seen as α-configuration nucleoside, but enters cells only via diffusion and is not transported by cellular nucleoside transporters. To enhance image contrast in comparison to [18F]FAZA our objective was to 18F-radiolabel an azomycin-2´-deoxyriboside with β-configuration ([18F]FAZDR, [18F]-β-8) to mimic nucleosides more closely and comparatively evaluate it versus [18F]FAZA. METHODS Precursor and cold standards for [18F]FAZDR were synthesized from methyl 2-deoxy-d-ribofuranosides α- and β-1 in 6 steps yielding precursors α- and β-5. β-5 was radiolabeled in a GE TRACERlab FXF-N synthesizer in DMSO and deprotected with NH4OH to give [18F]FAZDR ([18F]-β-8). [18F]FAZA or [18F]FAZDR was injected in BALB/c mice bearing CT26 colon carcinoma xenografts, PET scans (10min) were performed after 1, 2 and 3h post injection (p.i.). On a subset of mice injected with [18F]FAZDR, we analyzed biodistribution. RESULTS [18F]FAZDR was obtained in non-corrected yields of 10.9±2.4% (9.1±2.2GBq, n=4) 60min EOB, with radiochemical purity >98% and specific activity >50GBq/μmol. Small animal PET imaging showed a decrease in uptake over time for both [18F]FAZDR (1h p.i.: 0.56±0.22% ID/cc, 3h: 0.17±0.08% ID/cc, n=9) and [18F]FAZA (1h: 1.95±0.59% ID/cc, 3h: 0.87±0.55% ID/cc), whereas T/M ratios were significantly higher for [18F]FAZDR at 1h (2.76) compared to [18F]FAZA (1.69, P<0.001), 3h p.i. ratios showed no significant difference. Moreover, [18F]FAZDR showed an inverse correlation between tracer uptake in carcinomas and oxygen breathing, while muscle tissue uptake was not affected by switching from air to oxygen. CONCLUSIONS First PET imaging results with [18F]FAZDR showed advantages over [18F]FAZA regarding higher tumor contrast at earlier time points p.i. Availability of precursor and cold fluoro standard together with high output radiosynthesis will allow for a more detailed quantitative evaluation of [18F]FAZDR, especially with regard to mechanistic studies whether active transport processes are involved, compared to passive diffusion as observed for [18F]FAZA.
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Affiliation(s)
- Anna Schweifer
- Institute of Organic Chemistry, University of Vienna, Vienna, Austria
| | - Florian Maier
- Department of Preclinical Imaging and Radiopharmacy, University of Tübingen, Tübingen, Germany
| | - Walter Ehrlichmann
- Department of Preclinical Imaging and Radiopharmacy, University of Tübingen, Tübingen, Germany
| | - Denis Lamparter
- Department of Preclinical Imaging and Radiopharmacy, University of Tübingen, Tübingen, Germany
| | - Manfred Kneilling
- Department of Preclinical Imaging and Radiopharmacy, University of Tübingen, Tübingen, Germany; Department of Dermatology, University of Tübingen, Tübingen, Germany
| | - Bernd J Pichler
- Department of Preclinical Imaging and Radiopharmacy, University of Tübingen, Tübingen, Germany
| | | | - Gerald Reischl
- Department of Preclinical Imaging and Radiopharmacy, University of Tübingen, Tübingen, Germany.
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Kumar P, Elsaidi HRH, Zorniak B, Laurens E, Yang J, Bacchu V, Wang M, Wiebe LI. Synthesis and Biological Evaluation of Iodoglucoazomycin (I-GAZ), an Azomycin-Glucose Adduct with Putative Applications in Diagnostic Imaging and Radiotherapy of Hypoxic Tumors. ChemMedChem 2016; 11:1638-45. [PMID: 27377671 PMCID: PMC5095876 DOI: 10.1002/cmdc.201600213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/06/2016] [Indexed: 11/15/2022]
Abstract
Iodoglucoazomycin (I-GAZ; N-(2-iodo-3-(6-O-glucosyl)propyl)-2-nitroimidazole), a non-glycosidic nitroimidazole-6-O-glucose adduct, was synthesized, radioiodinated, and evaluated as a substrate of glucose transporter 1 (GLUT1) for radiotheranostic (therapy+diagnostic) management of hypoxic tumors. Nucleophilic iodination of the nosylate synthon of I-GAZ followed by deprotection afforded I-GAZ in 74 % overall yield. I-GAZ was radioiodinated via 'exchange' labeling using [(123/131) I]iodide (50-70 % RCY) and then purified by Sep-Pak™ (>96 % RCP). [(131) I]I-GAZ was stable in 2 % ethanolic solution in sterile water for 14 days when stored at 5 °C. In cell culture, I-GAZ was found to be nontoxic to EMT-6 cells at concentrations <0.5 mm, and weakly radiosensitizing (SER 1.1 at 10 % survival of EMT-6 cells; 1.2 at 0.1 % survival in MCF-7 cells). The hypoxic/normoxic uptake ratio of [(123) I]I-GAZ in EMT-6 cells was 1.46 at 2 h, and under normoxic conditions the uptake of [(123) I]I-GAZ by EMT-6 cells was unaltered in the presence of 5 mm glucose. The biodistribution of [(131) I]I-GAZ in EMT-6 tumor-bearing Balb/c mice demonstrated rapid clearance from blood and extensive renal and hepatic excretion. Tumor/blood and tumor/muscle ratios reached ∼3 and 8, respectively, at 4 h post-injection. Regression analysis of the first order polynomial plots of the blood and tumor radioactivity concentrations supported a perfusion-excretion model with low hypoxia-dependent binding. [(131) I]I-GAZ was found to be stable in vivo, and did not deiodinate.
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Affiliation(s)
- Piyush Kumar
- Department of Oncology, Cross Cancer Institute, University of Alberta, University Ave., Edmonton, AB, T6G 1Z2, Canada.
| | - Hassan R H Elsaidi
- Department of Oncology, Cross Cancer Institute, University of Alberta, University Ave., Edmonton, AB, T6G 1Z2, Canada
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Alexandria, El Sultan Hussein St. Azarita, Alexandria, Egypt
| | - Bohdarianna Zorniak
- Department of Oncology, Cross Cancer Institute, University of Alberta, University Ave., Edmonton, AB, T6G 1Z2, Canada
| | - Evelyn Laurens
- Clinical Imaging Research Centre, 14 Medical Drive, #B1-01, Singapore, 117599, Singapore
| | - Jennifer Yang
- Department of Oncology, Cross Cancer Institute, University of Alberta, University Ave., Edmonton, AB, T6G 1Z2, Canada
| | - Veena Bacchu
- Department of Oncology, Cross Cancer Institute, University of Alberta, University Ave., Edmonton, AB, T6G 1Z2, Canada
| | - Monica Wang
- Department of Oncology, Cross Cancer Institute, University of Alberta, University Ave., Edmonton, AB, T6G 1Z2, Canada
| | - Leonard I Wiebe
- Department of Oncology, Cross Cancer Institute, University of Alberta, University Ave., Edmonton, AB, T6G 1Z2, Canada
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